With increasing frequency, it has been necessary for state health authorities to close areas against the removal of bivalves therefrom because such areas have become polluted.
It is well known that the depuration of bivalves can be effected in 48 hours by exposing them to flowing unpolluted seawater closely corresponding to the seawater from which the bivalves were taken with respect to temperature, dissolved oxygen content, pH and salinity.
Depuration of bivalves can thus be effected by transporting them from a polluted area to an adjacent unpolluted area and using water therefrom in their treatment but with the risk of polluting that area with bacteria carried in the discharged water.
In prior proposals of which I am aware, the seawater being used has been subjected to ultraviolet radiation before or during the time when the bivalves were being treated therewith. For example, U.S. Pat. No. 3,641,982 provided an open end system in which water being discharged was also subjected to ultraviolet radiation. In U.S. Pat. No. 4,537,149, a closed system provided that the circulating seawater was also filtered and in U.S. Pat. No. 4,653,429, the seawater was derived from an aquifier and the container for the bivalves was exposed to ultraviolet radiation, after each batch was treated.